//
// Copyright (c) 2004-2024 Jaroslaw Kowalski <jaak@jkowalski.net>, Kim Christensen, Julian Verdurmen
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// * Redistributions of source code must retain the above copyright notice,
//   this list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
//
// * Neither the name of Jaroslaw Kowalski nor the names of its
//   contributors may be used to endorse or promote products derived from this
//   software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
//

namespace NLog.Internal
{
    using System;
    using System.IO;

    internal static class FileInfoHelper
    {
        internal const int MinReliableBirthYear = 1980;

        public static DateTime LookupValidFileCreationTimeUtc(this FileInfo fileInfo)
        {
            return LookupValidFileCreationTimeUtc(fileInfo, (f) => f.CreationTimeUtc, (f) => f.LastWriteTimeUtc);
        }

        private static DateTime LookupValidFileCreationTimeUtc<T>(T fileInfo, Func<T, DateTime> primary, Func<T, DateTime> fallback, Func<T, DateTime>? finalFallback = null)
        {
            DateTime fileCreationTime = primary(fileInfo);

            if (fileCreationTime.Year < MinReliableBirthYear && !PlatformDetector.IsWin32)
            {
                // Non-Windows-FileSystems doesn't always provide correct CreationTime/BirthTime
                fileCreationTime = fallback(fileInfo);
                if (finalFallback != null && fileCreationTime.Year < MinReliableBirthYear)
                {
                    fileCreationTime = finalFallback(fileInfo);
                }
            }
            return fileCreationTime;
        }

        public static bool IsRelativeFilePath(string filepath)
        {
            filepath = filepath?.TrimStart(ArrayHelper.Empty<char>()) ?? string.Empty;
            if (string.IsNullOrEmpty(filepath))
                return false;

            var firstchar = filepath[0];
            if (firstchar == Path.DirectorySeparatorChar || firstchar == Path.AltDirectorySeparatorChar)
                return false;

            if (firstchar == '.')
                return true;

            //on unix VolumeSeparatorChar == DirectorySeparatorChar
            if (filepath.Length >= 2 && filepath[1] == Path.VolumeSeparatorChar && Path.VolumeSeparatorChar != Path.DirectorySeparatorChar)
                return false;

            return true;
        }
    }
}
